Hoist



July 21, 1959 L. WQHALL 2,895,567

.- fester 'l/IHaZL July 21, 1959 L. w. HALL 2,895,567

' HOIST y l Filed June 6, 1957 2 Sheets-Sheet 2 ATTDRN EYS 218.95561. nolsr Lester W. l-lall, Livingston, Mont. Application Jung 6, i957, serial Nq. 664,028

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This invention relates to a, hoist or hand truck and lift.

The object of the invention is to provide a hoist which includes a means Vfor raising and lowering lifting arms whereby heavy objects can be readily elevated to a desired position without the necessity of lifting the objects by hand."

vAnother object ofthe invention is to provide a hand truck which includes a lift platform that is moved by means of an electric motor,"`and'whereby switches are provided for controlling actuation of the motor and lift platform or arms.

Y1A further object of the invention is to provide a hoist which is extremely simple and inexpensive to manufacture.

' Other objects and advantages will be apparent during the course of the following description.l

ln the accompanying drawings, forming a part of this application, and which like numerals are used to designate like parts throughout theA same.

Figure l `is a side 'elevational view showing the hoist of the present invention.

Figure 2 is a front elevational view of the hoist.

Figure 3 is a sectional view taken on the line 3--3 of Figure2. i

Figure 4 is a sectional ,View taken 0.11 the line 4-4 of Figure 2.

Figure 5 is a sectional view taken on the line 5-75 of Figure 2. A

Figure 6 is a sectional View taken on the line 6-6 of Figure 2.

Figure 7 is a view illustrating certain constructional details of the apparatus.

Figure 8 is a fragmentary elevational view illustrating a switch.

Figures 9 through 12 are schematic views illustrating the wiring diagram, and showing the parts in adjusted position.

Referring to detail to the drawings, there is shown a hoist or lift truck which includes a frame 10 that embodies a pair of spaced parallel channel members 11 which are U-shaped in cross section as shown in Figures 4, 5 and 6. Extending rearwardly from the lower ends of the channel members 11 are plates 12, and wheels 13 are journaled on the plates 12 through the medium of axles 9. Extending forwardly from the lower ends of the channel members 11 are rods 14.

Extending between the upper portions of the channel members 11 and secured thereto is a spacer member 15, which can also be used as a hand hold for pulling the hoist into hand truck position. Arranged below the spacer member 15 and secured to the channel members 11 is a cross piece 16 and a safety switch 17 and master switch 18 are supported adjacent the cross piece 16, there being an end piece 19 arranged at right angles with respect to the cross piece 16.

The hoist further includes a bushing 10 which is secured to the cross piece 16 intermediate its ends, and a screw member 21 has its upper end arranged in engagenited States Patent' fice 2 ment with the bushing 20. A strap 22 is arranged rearwardly of the screw member 21, andan automatic trip 23 forms part of a switch 24 which is held inpla'ceon the strap 22 by suitable securing elements 25,` 'Figure 2.'

The hoist further includes a movable lift plate 26 which hasv a bearing 27 that is arranged'in threaded engagement with the screw member 21, so` that as the screwmember' 21 is turned, the plate 26 will be shifted. Rollers 28 are positioned in the channel members`11, and the rollers .2S are journaled'in the 'ends of the lift plate 26 through the medium of axles 29. A'A pairV ofspaced parallel lift arms 30 extend forwardly fromthe lift plate 26 for en# gagement with a load such` as the load'38 shown' indotte'd linesinFigure l.

A means is provided for rotating the screw member 21 and this means comprises a sprocket 31 which'is mounted on the lower end of the screw'ni'ember' 21', andthe screw member 21A has4 its lower'end "engaging a' bushing" 32 which is supported'on a bottom 'piece 33. An endless' chain 34 is'trained over thev sprocket 31, andthe chain 34 is'also trained'over aA sprocket 35 on a drive shaft 36 which is driven by'a reversible motor 37. The motor 37. is connected to a support v'rnern'ber r39 through themedium of suitable securing elements such as`bolts` or screws 40, and a stop switch 52 is'also carried bythesupport inem#v bersg. ,Y A

Extending between the pair of channel members 11 and secured thereto, is a" pair of support bars V42., and a control box 43 `is connected "to the 'bars 42 -throflighth'e medium ofsecuringv elements 44, Figure 2.

There is further'provi'cled'a handl gripping means for the hoist, and thislm'eanscinpriseshandles 45,'whifch extend from the end piece Y19,'and 'are secured thereto, "and the handles" 45ha\`1"e'h'an'd grips 46 thereon", Figure'l. Body members 47 extend from the handles'v 45 'to the plates 12,` and braces iS/are connected tothe body membersw',

' Referring to Figure 7 of the drawings, it will be seen that extending" rearwardly from the plate'2`6 and secured thereto isv a linger 49 that is adapted toH vs '=.le"`c;`tively engage a push button Si! `cna switch 52, the syvitehw'SZ being secured in" place by sec'uririg"elern'ents`A 51'.rx 'Theinurne'ral 55 designates'an "outletwh'erby t'liehist can be"cni nected toa suitable vsourceo'feiectrical eiiergyfby means 0f an inlet wire or cable. The trip 23 is pivotall`y"munt ed as at 53, and the trip 23 serves to actuate a push button 54 which actuates the switch 24. As shown in Figures 9 through 12, suitable wires are provided for electrically connecting together the various switches and the motor 37.

From the foregoing it is apparent that there has been provided an electrically operated hoist which is especially suitable for lifting or handling articles such as the articles 3S which may be boxes of material or the like. In use, a plurality of the boxes or articles 38 are adapted to be supported on the lift arms 30 and by actuating the `motor 37, the shaft 36 will be rotated to thereby turn the sprocket 35. The hoist is adapted to be connected to a suitable source of electrical energy by means of a wire which leads to the outlet 55 and suitable wires connect the outlet 55 to the reversible motor 37 As the sprocket 35 turns, it moves the chain 34 which in turn rotates the sprocket 31, the sprocket 31 being mounted on the lower end of the screw member 21. As the screw member 21 rotates in one direction, the lift plate 26 will be raised since the bearing 27 on the rear of the lift plate 26 is arranged in threaded engagement with the screw member 21. By driving the motor 37 in the opposite direction, the screw member 21 can be rotated in the opposite direction so as to cause the lift plate 26 to move downwardly. The hoist is adapted to be moved from place to place as desired by means of the wheels 13, and the user can grip the hand grips 46 so as to tilt the hoist and guide it and move it to the desired location.

The operation of the hoist is as follows: By operating the motor 37, the lift plate 26 can be raised or lowered and with a plurality of boxes or articles 38 on the lift arms 30, the lift plate 26 and lift arms 30 will automatically move upwardly until the uppermost box 38 engages the trip 23, and when this uppermost box 3S' engages the trip 23, the circuit will be interrupted to the motor 37 so that upward movement of the platfrom 26 will automatically stop. Then, when the uppermost box 33 is removed from the pile of boxes on the lift arms 30, the trip 23 will drop by gravity on the pin 54 to thereby close the switch 24 so that the circuit to the motor 37 will again be completed whereby the lift plate 26 will continue its travel upwardly until the next box 38 engages the trip 23 and then the motor 37 will again bestopped and this cycle of operation will be repeated; In other words, the lift arms 30 automatically move upwardly as each successive box or article 38 is removed therefrom, so that the articles 38 can be conveniently removed from the lift arms. By moving the master switch 18, the direction of rotation of the motor 37 can be changed so that for example, the screw member 21 can be rotated in the opposite direction whereby the lift plate 26 and lift arms 30 can move downwardly, and as the lift plate 26 moves downwardly, the nger 49, Figure 7, engages push button 50 to thereby deenergize the switch 52 so as to interrupt the circuit to the motor 37 whereby the lift plate 26 will be automatically stopped at the proper position as it moves downwardly. Then, when it is desired to again cause the lift plate 26 to move upwardly, the control switch 18 is placed in forward position so as to again complete the circuit to the motor 37 whereby the screw member 21 will be rotated in the proper direction to cause the lift plate 26 to move upwardly. The switch 18 is the only manual control switch provided, and the others operate automatically.

Thus, it will be seen that there has been provided a hand truck which will permit heavy loads to be automatically lifted and the hand truck is useful in lifting heavy objects which may be on pallets whereby a person will not have to strain his back, and whereby the present invention can be also used for lifting heavy boxes, crates, shelves and the like and wherein these objects can be lifted to a desired elevational height and the device can also be used for sorting, lling or lowering objects or boxes in to a stack. i

I claim:

In a hoist, a frame including a pair of spaced parallel channel members, plates secured to and extending rearwardly of the lower ends of said channel members, an axle mounted at their inner ends in each of said plates and extending outwardly thereof at right angles thereto, wheels journaled on the outer ends of said axles, a bar extending outwardly from the lower end of each of said channel members and secured thereto, a safety switch extending between said pair of channel members and secured thereto, a cross piece extending between said channel members and secured thereto, a safety switch and a master switch supported by said cross piece, an end piece arranged contiguous to said cross piece and secured to said channel members, a bushing supported by said cross piece, a screw member having its upper end arranged in engagement with said bushing, a strap arranged rearwardly of said screw member and parallel to said channel members, an automatic trip switch mounted on said strap, a movable lift plate including a bearing arranged in threaded engagement with said screw member, rollers connected to said lift plate and positioned in said vchannel members, lift arms extending outwardly from said lift plate and secured thereto, a bottom piece secured to the bottom ends of said channel members, a bushing on said bottom piece for journalling the lower end of said screw member, a sprocket connected to the lower end of said screw member above said bushing, a support member extending between the lower portions of said channel members and secured thereto, a motor having a vertically disposed drive shaft is connected to said support member, a sprocket connected to the lower end of said drive shaft, chain means connecting the sprocket on the drive shaft of said motor to the sprocket on the lower end of said screw member, a stop switch carried by said support member, support bars extending between said channel members and secured thereto, a junction box connected to said support bars, and handles extending from said frame and secured thereto.

References Cited in the tile of this patent UNITED STATES PATENTS 2,362,853 Spiller Nov. 14, 1944 2,482,211 Reichardt Sept. 20, 1949 2,653,679 Hamilton Sept. 29, 1953 2,663,929 Carpenter Dec. 29, 1953 

